By Lara Salahi, ABC News
For more than 40 years, Lesley Kelly of Glasgow, Scotland, lived with third-degree burns that stretched over 60 percent of her body.

Kelly was 2 years old when she fell into a bathtub filled with hot water that scorched most of the right side of her body. She lost full range of motion around many of her joints.

"When you have bad scarring, the buildup is very thick and has no elasticity," said Kelly, 45, whose right elbow was most affected by the buildup of scar tissue. "The problem with thermal burn scarring [is that] it's hard to get the range of motion."

Kelly underwent numerous reparative surgeries through the years, but the scar tissue continued to grow back. The procedures did not lessen the look of her scars.

In 2011, Kelly underwent a new, experimental procedure that used stem cells from her own fat tissue to repair the buildup around her right elbow.

Surgeons cleaned the scar buildup around the elbow and used liposuction to pull fat from off Kelly's waist. They separated the fat cells from the stem and regenerative cells, which were then injected into the wound on Kelly's arm. The procedure took less than two hours.

Within months, Kelly was able to regain 40 degrees of motion that she had lost more than 40 years ago.

"If this technology was available earlier in my life, my scars would not have been as bad," said Kelly.

There are an estimated 50,000 to 70,000 burn cases each year in the U.S., according to the American Burn Association.

The stem cell therapy, approved in the U.K. to treat soft tissue wounds, is now gaining traction in the U.S.

Cytori Therapeutics, Inc., the biotechnology company that created the therapy, has been awarded a $4.7 million U.S. government contract to further develop the stem-cell treatment for thermal or radioactive burns.

The two-year contract with the Department of Health and Human Service's Biomedical Advanced Research and Development Authority supports preclinical and clinical research of the therapy. If certain endpoints are met, the contract could get extended and be worth $106 million, according to Cytori.

"This is one of the most exciting and promising self-therapies we've seen in regenerative medicine," said Robin Robinson, director of the Biomedical Advanced Research and Development Authority and the deputy assistant secretary for preparedness and response at the U.S. Department of Health and Human Services.

While still in its early development phases, one goal of the therapy is to be able to treat many burn victims following a "mass casualty event," according to a public statement by Cytori.

"The limited number of specialist surgeons and burn centers in the U.S. creates a public health need for a burn wound therapy that can be quickly and broadly applied by non-specialist medical personnel following such an event," said a public statement made by the company.

Robinson said the new therapy may have the potential to treat thousands of U.S. service members who have been injured by bombs.

For the first two years, the research will evaluate the therapy in animals before it can be tested clinically in humans.